<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>

<body>
    <script>
        let arr = [2, 6, 1, 77, 52, 25, 7], max = arr[0], min = arr[0];
        for (i = 0; i < arr.length; i++) {
            if (arr[i] > max) {
                max = arr[i];
            }
            else if (arr[i] < min) {
                min = arr[i];
            }
        }
        let cha = max - min;
        document.write(`最大值：${max},最小值：${min},他们的差为：${cha}`);
    </script>
</body>

</html>